SwingUtilities.invokeLater(new Runnable() {
public void run() {
Box upper = (Box)splitPane.getComponent(0);
upper.remove(0);
upper.add(nextToolbar, 0);
upper.validate();
nextToolbar.repaint();
toolbar = nextToolbar;
// The toolbar responds to shift down/up events
// in order to show the alt version of toolbar buttons.
// With toolbar switch, KeyListener has to be changed as well